Most optical targets are designed to work at a single wavelength or over a limited range of wavelengths (e.g., visible light), and are typically either light sources or light detectors, but not both. This makes it awkward to use them for boresighting (i.e. aligning) and calibrating modern optical sensor systems (e.g., a system under test (SUT)), which may fuse data from detectors working at multiple wavelength regions (e.g., visible, near infra-red, and thermal infra-red) and which may also include light sources (e.g., lasers). Such a sensor system typically consists of sub-assemblies, which must be precisely co-aligned so that for example, a laser beam emerges parallel to the field of the photodetector.
A typical solution might be an arrangement, which allows for several optical targets with various emission and detection capabilities to be inserted at the focus of an optical system where they can be viewed or illuminated by the SUT. Such an arrangement demands precise and repeatable mechanical insertions to be made. This is potentially a time-consuming and error-prone process, and it carries a risk of accidentally bumping and misaligning or damaging the optical system, thereby potentially causing laser beams from the SUT to pose a safety hazard.
As such, there is need for an improved technique for boresighting a SUT.